Michigan Senate forecast moves 16 points toward El-Sayed in three days

Our model now gives Democrat Abdul El-Sayed a 58 in 100 chance of winning Michigan's open Senate seat, against 42% for Republican Mike Rogers. Three days ago, in our run of August 16 at 10:15 PM ET, the same estimate was 43%. That is a shift of 15.7 points of Democratic win probability over three days.

The mean margin moved with it, from R+1.2 in the earlier run to D+1.3 now. The race remains close by our own reckoning: the model's 5th-to-95th-percentile band runs from R+9.6 to D+12.3, wide enough to contain comfortable wins for either candidate.

One survey arrived between the two runs. Susquehanna Polling & Research surveyed 800 likely voters from August 11 to 17, finishing after the earlier run, and found El-Sayed at 46% and Rogers at 39%. That is the widest Democratic margin of the three Michigan polls in our set. The other two, both from TIPP Insights and fielded August 6 to 10, had El-Sayed at 43% to Rogers' 39% among 1,528 registered voters and at 45% to 42% among 1,215 likely voters. Those two were already reflected in our previous run.

The payload does not let us separate how much of the three-day move came from the Susquehanna numbers and how much from other inputs to the model, so we will not attribute all of it to the poll. Nationally, our Senate picture is close to even: the model gives Democrats a 49% chance of winning control and Republicans 51%, with a mean of 50.2 Democratic seats. Democrats need 51 seats for a majority and Republicans 50, because the vice president is a Republican and a 50-50 tie goes to their side. Michigan is one of the seats that decides which side of that line the chamber lands on.